Bluetooth – a general communication standard


Bluetooth technology for wireless data transfer is very popular and is available for many applications. Bluetooth and Bluetooth Low Energy can be found primarily in computers, tablets, smartphones, cars, speakers, as well as in smart devices such as smartwatches or fitness bands.

The main assumption of the technology is communication over short distances while maintaining significant energy efficiency. Two-way communication takes place in half-duplex or full-duplex mode.

Bluetooth is part of an open communication standard described in the IEEE 802.15.1 specification. The specification defines three classes of transmitting power with ranges of 1 meter, 10 meters and 100 meters respectively in open space. The standard is based on radio waves operating in the ISM 2.4GHz frequency band.

The first version of the standard was presented in 1999. under the designation Bluetooth 1.0. It defined the throughput as low as 21kb/s. The next version 2.0 allowed to increase the bandwidth to 2.1Mb/s. Bluetooth 3.0 + High Speed ​​is already 24Mb/s. Most of the current devices use Low Energy versions 4.1 and 4.2 – standards intended for use in IoT wearables, i.e. bands and smartwatches. Due to the growing requirements in the context of a higher level of security, energy efficiency, speed and ease of making connections, the current newer devices already use Bluetooth LE 5.0, which allowed to achieve a transfer of 2Mb/s for wearables and 50Mb/s for others with a real operating range up to 140 meters. Bluetooth LE 5.2 expands the previous version with the additional function of connecting two devices at the same time.

Bluetooth LE in STMicroelectronics products

There are two solutions – systems in the form factor of a ready-made module or based on the SoC (System on Chip) integrated circuit.

SoC integrates Bluetooth LE technologies connected, depending on solution, with a microcontroller. The user has to design the omnidirectional elements (radio path, power supply and others), and then carry out certification in order to achieve compliance with the Bluetooth standard – the need to pay the appropriate certification fees.

SoC solutions are based on a network or application processor.

The network processor features a pre-programmed BLE radio stack. Data access is possible via the UART or SPI communication interface. They require an external microcontroller, in which the user’s application will be placed. This approach eliminates the risk of implementing BLE functionality into an existing product.

The application processor eliminates the need for external control or companion microcontroller to complement memory and/or peripherals. The user application and the radio stack can run on the same and single product. This makes it possible to design new devices at a lower cost by reducing the BOM.

In data pump mode, our BlueNRG SoC lets developers easily add BLE functions to an existing product via a basic UART-toBLE bridge (hosted over BlueNRG). This approach also minimizes integration and deployment risks as well as reduce main CPU processing.

ST Flyer BlueNRG-Mesh Bluetooth Low Energy networking for a smarter: STM 1

BlueNRG-2N is the Network processor version of BlueNRG-2,with the BLE 5.2 certification. The STMicroelectronics BLE stack is stored into the on-chip non-volatile Flash memory and it can be easily upgraded via SPI/UART as well through the dedicated STMicroelectronics software tools. The operating temperature range has been extended to 105°C.

Subsequent versions of SoC BlueNRG-1 and BlueNRG-2 in the BLE 5.2 standard have already been equipped with an application processor with a Cortex M0 core operating at a frequency of 32MHz and using 24kB of RAM memory. The difference between them is the size of the Flash memory (160kB for BlueNRG-1, 256kB for BlueNRG-2). More peripherals on board including. 2xSPI, 2xI2C and an additional variant of the QFN48 housing.

BlueNRG-LP is a system that supports 128 concurrent connections. It is the first SoC with a Long Range mode, 2Mbps Data Rate and an advertisement extension mode. It embeds state-of-art 2.4 GHz RF radio IPs combining unparalleled performance with extremely long-battery lifetimeThe focus was on the radio chip and a microcontroller. A microcontroller with a more efficient Cortex-M0 + 64MHz core, using 256kB Flash and 64kB of RAM, was installed. Security aspects increased: TRNG random number generator, AES 128-bit encryption, PKA public key, CRC computing unit and others.

ST Flyer BLUENRG-LP WIRELESS PROCESSOR  Future-ready Bluetooth LE 5.2 programmable System-on-Chip: STM 2


The STM32WB series, multiprotocol application processor, supports the Bluetooth Low Energy 5.2 standard with the 2Mbps and advertising extension , as well as Zigbee and Thread technologies. This series can support more than one protocol in parallel in static or dynamic manner. For example, in static mode, application can switch from exclusive Zigbee operation to Bluetooth Low energy exclusive operation , while in dynamic mode, radio quickly switches between protocols managing time sharing and keeping the network installed.

ST Flyer STM32WB WIRELESS SERIES Bluetooth LE 5.2 & IEEE 802.15.4: STM 3

The STM32WB includes a dual core architecture with a Cortex M4 running at 64MHz designed for user applications and a Cortex M0 + running at 32MHz for radio and security. Such 2 in 1 solution brings security protections to avoid hacking and cloning. The low-power modes and microcontrollers peripherals are drawn from the STM32L4 MCU series to the STM32WB series making it optimized for battery operated devices and easy porting through STM32 family and its seamless STM32Cube ecosystem when devices go to wireless.

This STM32 wireless series offers a wide portfolio with regards to embedded memory: from 256KB up to 1MB of flash, and wide peripherals set, proposed with large package flavors to match high end products as well as simple point to point applications.



STM32WBx5 products are super set series, full access to features like high transfer 2Mb/s, +6dBm output power, concurrent modes, rich peripherals like USB, Quad-SPI, SAI, LCD controller and more security on board – CKS (Customer Key Storage) and wide temperature range up to 105°C.

The STM32WBx5 series includes a various types of packages and a ready to use  STM32WB5MMG module addressing time to market optimization and simplified certification process.

The STM32WBx0 series belongs to the Value Line family. It proposes fewer peripherals, fewer radio flavors with single protocol, up to + 4dBm transmit power, and one QFN48 housing available. Suitable for entry level devices requiring essential features with cost optimization.

ST Flyer STM32WBx0 VALUE LINE Bluetooth LE 5.2 & IEEE 802.15.4: STM 4  

In addition to the SoC, there are also ready-made Bluetooth LE modules with integrated antenna. There is no need to go through the full certification process. You only need to pay the Bluetooth SiG membership fee. The process is much shorter and cheaper, thanks to the manufacturer providing the necessary documents together with the module.

Examples of Bluetooth LE modules:

Bluetooth LE STMicroelectronics modular solutions are divided into three basic families

BlueNRG-M0 are based on BlueNRG-MS systems with a network processor. The main features are
+6dBm output power, chip antenna and a balun circuit with an integrated filter on board. The M0A subfamily is a richer version with a built-in choke that can use from an energy-saving SMPS converter, consuming less energy in active mode. It also has soldered 32kHz quartz, which allows you to enter the low-power mode. M0L has no choke and quartz and works with LDO.

BlueNRG-M2 is based on BlueNRG-2 application processor. Similarly, the M2SA subfamily is a richer version. Main features are +5dBm output power, built-in choke, SMPS, 32kHz quartz and chip antenna. M2SP has a power of +7dBm, no choke, quartz, work with LDO, PCB antenna.

ST Flyer BlueNRG Modules  Simplifying the adoption of Bluetooth Low Energy technology: STM 5

The STM32WB5MMG is based on the STM32WB55 SoC within optimized and self-sufficient BOM. Provides best-in-class RF performance thanks to good receiver sensitivity and high signal output power. Low-power functions enable longer battery life. The STM32WB5MMG does not require any specific knowledge of radio frequencies and is the best way to accelerate development and reduce the associated costs.

The presentation about STM32WBxM Wireless Modules available here: click

STM32WBxM WIRELESS MODULES Bluetooth LE 5.2, Zigbee 3.0 and Thread  available here: STM 7

It comes with following main features:

  • 1MB Flash memory, 256kB SRAM,
  • BLE 5.2, Zigbee 3.0, OpenThread,
  • dynamic and static concurrent modes,
  • output power +6dBm,
  • range: up to 75 meters,
  • antenna chip,
  • integrated SMPS,
  • 2xSPI, 1xQSPI, 1xUSART, 1xLPUART, 2xI2C, 1xADC SAR, 2xComp, 1xUSB, 1xSAI, display driver,
  • built-in security features as: AES 256-bit, TRNG, PKA, CKS, CRC.
  • Certifications: CE, FCC, IC, JRF, SRRC, RoHS, REACH, GOST, KC, NCC
  • Two layers PCB compatible (using external raw pins only)



Read more on the STMicroelectronics Blog:

NUCLEO-WB15CC: Bringing Bluetooth and Touch Sensors to More Developers
STM32WB15 and STM32WB10, 320KB of Flash and 48 KB of RAM to Bring Bluetooth 5.2 to Cost-Effective Applications

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